Luminous and thermal characteristics of Er3+/Yb3+ co-doped WO3: a heat-sensitive micro-particle

Er3+/Yb3+ co-doped WO3 micro-particles were prepared by sol-gel method. The green upconversion (UC) luminescence and the photothermal characteristics have been investigated. The center wavelength of the green luminescence shifted to short wavelength with the increase of pumping power. For the W2 sample (98.9W2O3-0.1Er2O3-1Yb2O3), the laser-induced temperature can rise up to ∼85 °C under 975 nm excitation. These results indicated that an optical heating of the nanoparticles can be realized, and the temperature rise of the nanoparticles can be investigated via the UC luminescence process. These researches will be meaningful to explore high-quality photothermal materials.